The described embodiments related to management of wireless networks, and more particularly, to apparatus and methods for mobile terminal-based radio resource management and wireless network optimization.
Currently, wireless systems, such as Universal Mobile Telecommunications System (UMTS) and Code Division Multiple Access (CDMA) systems, rely on network-based Radio Resource Management (RRM). At the network side, a Radio Network Controller (RNC) or some similar network device, is responsible for radio resource policy making and enforcement. In this regard, the RNC configures all of the radio resource parameters, the radio resource measurements and makes the handover decisions for all of the connected mode mobile terminals in the network. When the mobile terminal is in idle mode (no active connection), the mobile terminal can make handover decisions independently from the RNC. Handover in idle mode is called “cell reselection” and although the handover decisions are performed independently by the mobile terminal, the parameters setting the criteria for cell reselection are set by the RNC.
Recent developments in the network infrastructure design have provided for RRM granularity at the cell level. Thus, a RNC is capable of providing uniform configuration to all of the mobile terminals within an area served by a given cell. For example, a given RNC is able to configure and manage the hard and soft handover process uniformly across all the mobile terminals currently located in a given cellular area serviced by the RNC. In other words, all of the mobile terminals within the area served by a given cell will have the same handover criteria and the same handover thresholds, collectively referred to as RRM parameters. Conversely, the RRM parameter configuration may be configured such that the parameters vary from one cell to another.
Uniform configuration across the entire cell does not take into account the heterogeneous nature of the mobile terminals that may reside in any one area served by a cell. For example, a cell may serve an area anywhere from 10 km2 to 30 km2 and, therefore, the mobile terminals that reside in the area served by the cell may widely differ in terms of mobility patterns and may further experience widely varying radio environments. For example, the cellular area may include mobile terminals that are in transit, such as mobile terminals in use by high-speed highway travelers or conventional municipal travelers, and mobile terminals that are used by pedestrians or stationary users located either outdoors or indoors. All of these mobile terminals will vary in terms of radio frequency conditions and, as such, will have variances in terms of radio resource requirements. Current RRM techniques, which, as noted, are limited to configuration and optimization of the mobile terminals at the cellular level, do not provide for management of resources and parameters on a mobile terminal-by-mobile terminal basis to optimize the experience of a given mobile terminal.
For example, in a hypothetical inter-Radio Access Technology (inter-RAT) handover scenario, where a call is transferred from one system to another, the RRM of the cell may be configured such that the handover decision process from the UMTS to the Global System for Mobile (GSM) telecommunications occurs if the Received Signal Code Power (RSCP) falls below a specified cell-wide threshold. The cell-wide threshold may be justifiable, for example, for mobile terminals in transit, however, the threshold may trigger handover to the GSM in instances in which the radio signal is sufficiently adequate for a stationary mobile terminal, such as a workplace user. In effect, all of the mobile terminals in the cellular area are provided uniform RRM and the variance in mobile terminal radio conditions are not taken into account in the radio resource management process. This results in less than ideal network performance and does not account for the unique radio characteristics experienced by each mobile terminal in the network.
Therefore, a need exists to develop methods and devices that provide for RRM at the mobile terminal level. By providing for RRM at the mobile terminal level, network optimization may be increased such that mobile terminals with widely varying radio conditions can be accounted for and adjustments made at the mobile terminal level to optimize the performance of each individual mobile terminal.